New Study Highlights Hip Replacement Failure

Results of a recent study have revealed that metal-on-metal hip replacement failure rates are two-to-three times higher than in other types of artificial implants.

In the January issue of the Journal of Bone and Joint Surgery, the American Association of Hip and Knee Surgeons, the American Academy of Orthopaedic Surgeons, and The Hip Society released a joint statement warning patients of the risks associated with metal-on-metal hip implants.

“It has been estimated that since 1996 more than 1,000,000 MoM articular couples have been implanted worldwide,” according to the statement. “However, with increasing clinical experience, the national joint registries have recently reported the failure of total hip arthroplasty (THA) with MoM bearings to be two to threefold higher than contemporary THA with non-metal-on-metal bearings.”

According to the statement, adverse tissue reactions caused by metal debris is cited as a cause of the high rates of failure experienced in patients with metal-on-metal implants.

The final blow for metal-on-metal designs?

The joint statement doesn’t call for surgeons to never use metal-on-metal hip implants, though it is not the first time that medical professionals have raised concern about the effectiveness and potential dangers of metal hip and knee prosthetics.

This type of hip replacement originally became popular as an alternative for young, active patients, as it was supposedly more durable. When the metal-on-metal design became popular, many orthopedic surgeons quickly became concerned with unexpectedly high rates of failure experienced by patients.

As metal pieces rub against one another during normal usage, surgeons noted that cobalt and chromium debris could shed into the body. This led to higher than expected failure rates in some models, and a fear that the debris was causing metallosis, a form of blood poisoning that can cause the development of pseudotumors (non-cancerous dead tissue).

Reports of complications spread

Problems associated with metal-on-metal implants gained national attention in August 2010, after the Depuy ASR XL Acetabular hip replacement and resurfacing systems were recalled from the market. DePuy Orthopaedics, a division of Johnson & Johnson, announced the company’s artificial hips had a failure rate of 13 percent.

Some experts believe the failure rate is even higher, and that around one-third of all DePuy ASR hip implants will fail within six years.

Following the DePuy ASR recall and the high failure rates associated with other metal-on-metal implants, surgeons began to question the effectiveness of other metal hip implants. It remains to be seen if the the joint statement in JBJS will cause some orthopedic surgeons to stop using metal hip designs altogether.

Hip replacement recall

DePuy Orthopaedics isn’t the only manufacturer to issue a recall of metal-on-metal hip device. In July 2008, there was a voluntary recall of some components used in connection with Zimmer’s Durom Acetabular hip system. In June 2012, Stryker Corporation recalled its Rejuvenate Modular and ABG II modular-neck hip systems.

Manufacturers continue to face thousands of lawsuits regarding hip replacement failure, brought by injured patients throughout the country. Hip implants are typically expected to last 15 to 20 years, but most plaintiffs allege they needed revision surgery to replace the devices just a few years after receiving them.

Currently, more than 12,000 DePuy ASR hip lawsuits have been filed against Johnson & Johnson. The manufacturer is expected to pay more than $2.4 billion in damages to resolve approximately 8,000 cases under a proposed settlement program.

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